Pentecostals seem to have a special appeal to impoverished and/or oppressed people, IMHO.
In the hills of east Tennessee where I spent my earliest years, both of my grandfathers were country preachers. People were drawn to their churches (shacks in the woods) because of the spirit, evidences of holy spirit, and purity and authenticity of the worshippers. Pentecostals are into self-sacrifice and sincerity of heart, at least the ones I knew. Having a real, authentic experience with the holy spirit was their focus. Yes, it produces loud shouting and strange-looking gyrations, but it's a release from the sorrows of endless labor and want.
Because Pentecostals, for the most part, are true believers, they share their faith with everyone by example if not directly.
Regards,
SandraC